This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7110 from an application for WASHING MACHINE earlier filed in the Korean Industrial Property Office on Apr. 23, 2001 and there duly assigned Serial No. 21793/2001 by that Office.
1. Field of the Invention
The present invention relates to washing machines and, more particularly, to a washing machine provided with a twistable washing tub within a perforated spin-drying tub for improving its cleaning effect.
2. Description of the Prior Art
As shown in FIG. 1, a conventional washing machine comprises an outer tub 1 containing water therein, a perforated spin-drying tub 2 concentrically and rotatably set within the outer tub 1, and a pulsator 3 rotatably set within the spin-drying tub 2 and agitating laundry and washing water within the tub 2. The washing machine also has a drive unit for rotating the spin-drying tub 2 and the pulsator 3. This drive unit comprises a reversible drive motor 4 and a power transmission device 5. The motor 4 is installed on the outer surface of the bottom wall of the outer tub 1, while the power transmission device 5 transmits the rotating force of the motor 4 to the spin-drying tub 2 and the pulsator 3.
During an operation of the washing machine, the pulsator 3 within the spin-drying tub 2 is repeatedly rotated in opposite directions by the rotating force of the drive motor 4, thus agitating the washing water and laundry within the spin-drying tub 2 and cleaning the laundry.
The conventional washing machine is designed in that the laundry cleaning effect is only accomplished by the frictional action of the laundry within the swirling washing water. Therefore, the washing machine is problematic in that it is almost impossible for the washing machine to accomplish desired cleaning effect while washing exceedingly dirty laundry since the machine may fail to wash off the dirt from the laundry.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a washing machine, which is provided with a twistable washing tub designed to be repeatedly twisted and untwisted during a washing process, thus repeatedly compressing and releasing the laundry and improving the laundry cleaning effect.
In order to accomplish the above object, the present invention provides a washing machine, comprising: an outer tub containing water therein; a drive unit installed at a position outside the outer tub to generate rotating force; and a washing tub rotatably set within the outer tub and connected to the drive unit at its lower portion, the washing tub being twistable and deformable at its sidewall to compress the laundry contained therein when the washing tub is rotated by the rotating force of the drive unit.
In the washing machine, the washing tub comprises: a lower rotary disc connected to a washing tub shaft rotated in conjunction with the drive unit; a plurality of twistable bars upwardly extending from the edge of the lower rotary disc, each of the twistable bars being made of flexible and elastic material; and an upper ring holding top ends of the twistable bars.
The washing machine further comprises: a spin-drying tub installed outside the washing tub to surround the washing tub, the spin-drying tub being selectively rotated by the drive unit to spin-dry the laundry, with the upper ring being mounted to the upper end of the spin-drying tub.
The washing tub shaft comprises first and second shaft parts coupled together such that the washing tub shaft is extendible in an axial direction, thus allowing the lower rotary disc to be vertically movable in opposite directions.
The washing machine further comprises an elastic member for normally biasing the lower rotary disc downward in a vertical direction. In addition, the first and second shaft parts of the washing tub shaft are hollow shaft parts, and receive the elastic member therein.
In another embodiment, the second shaft part is a hollow shaft part fitted over the first shaft part, and has a flange at its upper end, with the elastic member being connected to both the flange and the lower rotary disc at its opposite end.
In another embodiment, the washing machine further comprises: a spin-drying tub installed outside the washing tub to surround the washing tub, the spin-drying tub being selectively rotated by the drive unit to spin-dry the laundry; and a guide means for guiding a vertical movement of the upper ring relative to the spin-drying tub, the guide means being provided on both the inner surface of the spin-drying tub and the upper ring.
The guide means comprises a plurality of guide rails vertically formed on the inner surface of the spin-drying tub, and a plurality of guide grooves formed on the upper ring at positions corresponding to the guide rails, with an elastic member connected to the upper ring and the upper end of the spin-drying tub and normally biasing the upper ring upward in a vertical direction.
In the washing machine, a cylindrical bellows member covers a gap between the upper end of the spin-drying tub and the upper ring.
In addition, one or more pulsating blades are formed on the top surface of the lower rotary disc to generate active swirling currents in the water during a rotating action of the rotary disc.